Commonly a surfactant is an organic compound having at least one functional group that tends to be hydrophilic or water-seeking and at least one other functional group that tends to be hydrophobic or water hating. These functional groups can be assembled in surfactant molecules wherein the solubility, properties, location and relative sizes of the functional groups determines the surfactant properties of the compound.
The practical application of surfactants generally depends upon the properties of the surfactant in aqueous solution. Important properties of surfactants include the wetting power of aqueous solutions of surfactants, the ability of surfactants to dissolve normally water insoluble substances, the ability of surfactants to stabilize dispersed systems such as emulsions or suspensions, the ability of detersive systems (systems containing a detergent) to clean, the ability of surfactants to foam or resist foaming in aqueous solutions, the ability of surfactants to sanitize and others. Many types of surfactant molecules are known and are broadly classified as anionic, cationic, nonionic and amphoteric. Surfactant molecules can contain one or more of a variety of hydrophilic functional groups such as hydroxyl groups, ether linkages, groups derived from alkylene oxides such as ethylene oxide and propylene oxide; quaternary amines, ester linkages, amino groups, amido groups, carboxylic acid groups, sulfonic acid groups, and can contain one or more of hydrophilic groups such as alkyl groups, unsaturated alkenyl or alkynyl groups, aromatic groups, fatty acid residues, and many others. Such functional groups can easily be classified by the skilled artisan into groups that tend to be hydrophilic and groups that tend to be hydrophobic. However, the properties of the resulting surfactant molecules are not directly predictable since the contribution of each functional group is not fully quantifiable.
In general, high molecular weight tertiary amine oxide compounds have been recognized in the art. The prior art is primarily directed to two classes of surfactants which have been examined in great detail and have useful high foaming surfactant properties. These compounds are typically the mono-(C.sub.8-18 alkyl)di(methyl) amine oxide compounds of the formula: ##STR1## wherein R is a C.sub.8-18 alkyl group and the mono-(C.sub.8-18 alkyl)di(C.sub.2-3 alkanol) amine oxide compounds of the formula: ##STR2## The commercial use of such amine oxide classes are discussed in Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 1, pp. 32-47, Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 19, pp. 556-559. See also Burton, U.S. Pat. No. 4,421,740, Ando et al, U.S. Pat. No. 4,337,165, Yoshikawa, U.S. Pat. No. 4,320,033, Russell, U.S. Pat. No. 3,843,395, Olson et al, U.S. Pat. No. 3,808,311, Morton, U.S. Pat. No. 3,686,025, Heinz, U.S. Pat. No. 3,470,102, Drew, U.S. Pat. No. 3,441,612, Wakeman et al, U.S. Pat. No. 3,270,060, Lang, U.S. Pat. No. 3,086,943, Drew et al, U.S. Pat. No. 3,001,945, Pilcher et al, U.S. Pat. No. 2,999,068, and British Pat. No. 1,294,642.